Progress has been made toward the sequential resolution and reconstitution of specific components of a hormone-sensitive adenylate cyclase system by a combination of biochemical and genetic manipulations. These studies will be extended toward the ultimate goal of elucidation of the mechanisms of interaction of these components and of the regulaton of their interactions by hormones (such as beta-adrenergic agonists, prostaglandins, and glucagon), regulatory purine nucleotides, and adventitious compounds such as fluoride and cholera toxin. Individual components of the system will be purified by conventional and/or immunological techniques, and they will be characterized in isolation as a prelude toward meaningful description of their interactions. Assays of increasing precision for individual components of the system will, in addition, allow exploration of mechanisms of more chronic regulation of the rate of synthesis of cyclic AMP.